Washington, DC — According to news reports, the shooters who killed 14 people and wounded 21 more in San Bernardino, California on Wednesday used a DPMS AR-15- style assault rifle equipped with a “bullet button,” a minor design feature that, because of a definitional loophole, has allowed gunmakers to circumvent the state’s ban on assault weapons. News reports say the shooters fired 65 to 75 assault rifle rounds at the scene and an additional 76 rounds from the weapons in their confrontation with law enforcement.

Another “bullet button” assault rifle, a Smith & Wesson M&P15, was used in the 2013 shooting at Los Angeles International Airport that killed a TSA agent and wounded several others.

“California law bans semiautomatic rifles with the capacity to accept a detachable
ammunition magazine and any one of six enumerated additional assault weapon characteristics (e.g., folding stock, flash suppressor, pistol grip, or other military-style features).

“However, in California an ammunition magazine is not viewed as detachable if a ‘tool’ is required to remove it from the weapon. The ‘bullet button’ is a release button for the ammunition magazine that can be activated with the tip of a bullet. With the tip of the bullet replacing the use of a finger in activating the release, the button can be pushed and the detachable ammunition magazine removed and replaced in seconds. Compared to the release process for a standard detachable ammunition magazine it is a distinction without a difference.”

As a result, even though the DPMS AR-15 assault rifle used in the shooting could accept a detachable ammunition magazine and would otherwise be banned, because it was outfitted with a “bullet button” it is treated under the law as if did not have a detachable ammunition magazine, making it legal to buy and own in California.

Numerous assault weapon manufacturers, including DPMS and Smith & Wesson, market “bullet button” assault weapons for sale in California, which manufacturers often euphemistically call “California Compliant.” A Smith & Wesson M&P15 assault rifle was also used in the San Bernardino shooting, although it is not known for certain whether this weapon was a “bullet button” assault rifle. (Update: Another news report now states the Smith & Wesson M&P15 assault rifle was also equipped with a bullet button.)

The VPC study notes that one reason the gun industry has targeted California is that because of its longstanding regulation of assault weapons, ownership of such firearms in the state is low.

VPC Executive Director Josh Sugarmann states: “The gun industry is expert in marketing military-bred weapons with a wink and a nod, constantly working to skirt federal and state laws with no concern for the real-world life and death impact of its cynical actions.”

The VPC study Bullet Buttons: The Gun Industry’s Attack on California’s Assault Weapons Ban can be found here:

The Violence Policy Center is a national tax-exempt educational organization working for a safer America through research, investigation, analysis, and advocacy. The VPC provides information to policymakers, journalists, organizations, advocates, and the general public. Click here to learn more.